How Principal Engineers Shape Documentation as a Product + Punch List Lagniappe

I’ve written plenty about documentation already (just recently here and here), so consider this a continuation of that thread. If you missed the earlier pieces, I’ll drop placeholders for them at the end. For now, let’s talk about a role that quietly makes or breaks the whole idea of “documentation as a real product” inside an engineering organization: the principal engineer.

People love to treat documentation like something you toss over the wall to a tech writer or leave in a Jira ticket until someone “has time.” A principal engineer doesn’t get to play that game. If anything, they’re the last person who can afford to pretend docs are an afterthought, because they’re the ones who end up carrying the blast radius when those docs fail. And they will fail if the principal engineer isn’t shaping them with the same rigor they apply to architecture, APIs, and operational design.

A principal engineer isn’t writing every page. They’re not your documentation vending machine. What they do is far more structural. They set the expectations for how documentation fits into the engineering lifecycle. They define the standard for what good looks like. They remove ambiguity. They make it impossible for other engineers to shrug and say, “I didn’t know that needed to be documented.” And they act as the connective tissue between engineering, product, and whoever else depends on what the system actually does versus what people assume it does.

At a practical level, a principal engineer does a handful of things that influence documentation whether anyone realizes it or not. They shape the architecture in a way that’s explainable instead of inscrutable. They make early calls on naming, patterns, boundaries, and contracts that determine whether documentation will be coherent or a pile of tribal-knowledge hacks. They create example implementations, minimal working demos, starter kits, and reference paths that become the backbone of the docs others write. They help the team decide what needs deep explanations and what deserves a quickstart. They push back when something is too complex to document cleanly, because that usually means it’s too complex, period.

And if the team is moving toward AI-driven docs, a principal engineer ensures that both the architecture and the content are compatible with that direction. They know that garbage in means garbage out, and they make sure the underlying systems and API surfaces generate signals that AI tools can work with. They’re the ones who see that the structure of the system influences the structure of the documentation, and they take responsibility for both.

Most importantly, a principal engineer doesn’t wait for docs to catch up. They bake documentation requirements into design reviews. They insist on “docs before release” as a non-negotiable. They challenge engineers when something is explained poorly or not at all. They mentor mid-level engineers on how to produce docs that reflect how the system actually works. They treat documentation as part of the architecture, not a accessory to it. And when the company claims documentation matters and behaves otherwise they’re usually the ones forcing the uncomfortable conversation that snaps everyone back into alignment.

Good documentation doesn’t happen because someone “writes well.” It happens because the most technically senior people refuse to let it rot. When principal engineers take documentation seriously, the rest of the organization follows. When they don’t, nothing saves it; not AI, not templates, not style guides. The tone is set at the top of the technical ladder.

And if we’re being honest, principal engineers are the ones who need great documentation the most. They’re the ones trying to scale their influence, cross boundaries, and keep the organizational web from collapsing into chaos. Documentation is how they extend their reach without being a gatekeeper or a bottleneck. It’s how they scale themselves without cloning themselves.

So yes, principal engineers architect systems. Yes, they design patterns, evaluate tradeoffs, and push strategy forward. But the part people underestimate is this: they architect the documentation ecosystem too. If they don’t, rarely anybody else will. And the cost of that failure is paid in pager calls, onboarding pain, brittle systems, feature regressions, and teams that have no idea why things are built the way they are. The calamity can be seen coming from months away!

If you want documentation to be a real product, not a chore, your principal engineers have to treat it like infrastructure. It’s that simple. After all, documentation has always been a product, the top principal engineers will manage that accordingly!

Principal Engineer’s Punch List Lagniappe for Docs

• Make architectural decisions that are explainable, not mystical.
If you can’t document it cleanly, you probably designed it poorly. Treat that as a signal, not an inconvenience.

• Kill ambiguity at the source.
Naming, boundaries, contracts, API shapes—lock them down early. Docs can’t compensate for a wobbly system.

• Loop documentation into every design review.
A design that can’t be described is a design that isn’t ready.

• Demand “docs before release” with zero exceptions.
A feature without documentation is unfinished work. Ship it when it’s whole, not when it’s merely “working.”

• Create the canonical reference paths.
Examples, starter kits, initialization patterns—these become the backbone of everything others write. Don’t leave them to chance.

• Draw the line between quickstarts and deep dives.
Everything doesn’t need a wall of text, but everything does need a clear entry point.

• Reject undocumented complexity.
If documenting something feels painful, the system is probably too complex. Simplify the system, not the explanation.

• Mentor engineers on writing technical truth, not technical theatre.
Your mid-levels don’t magically know how to write meaningful docs. Show them the difference between describing code and explaining behavior.

• Keep product, engineering, and operations aligned through documentation.
Docs are the connective tissue. Guard that connective tissue like infrastructure, because that’s what it is.

• Ensure your architecture produces AI-tractable signals.
Good telemetry, clear contracts, structured interfaces—AI tooling depends on your technical hygiene.

• Don’t tolerate tribal knowledge masquerading as “context.”
If it matters, write it down. If it’s repeated twice, automate it. If it’s repeated three times, document it.

• Treat documentation debt like operational risk.
Because it is. Missing docs cause outages, regressions, slowdowns, and bad decisions. Act accordingly.

• Protect future you.
You’ll need this documentation more than anyone. You’re the one crossing teams, solving the weird edge cases, and getting pulled into the architectural archaeology. Write for that version of yourself.